[Feat] Merge testsuite and test_suite directories for v.surf.rst. about grass

[echoix]

If they are correctly picked up by gunittest, yes.
By correctly picked up I mean that they are able to fail if they need to fail. For example, locally messing up the inputs or expected output, and making sure that gunittest fails.

testsuite should be the one kept.

[HuidaeCho]

We need a unified directory name. From the contents of both directories, testsuite seems to be newer.

[echoix]

testsuite is the (only) one that gunittest looks for. tests is for pytest (until our unittest-based tests run with pytest, for now they can't).

test_suite or any other shell file not in the expected folder structure simply aren't run.

[HuidaeCho]

testsuite is the (only) one that gunittest looks for. tests is for pytest (until our unittest-based tests run with pytest, for now they can't).

test_suite or any other shell file not in the expected folder structure simply aren't run.

Good to know that!

[echoix]

See also

#3362

#3358

And

#3358 (comment)

I didn't go any further since with the time I had, there weren't any more that could simply be renamed without bigger changes with the files themselves.